package it.nm.unipicontrol.gcm.server;

import java.io.IOException;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.net.ssl.SSLSocketFactory;

import org.jivesoftware.smack.ConnectionConfiguration;
import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
import org.jivesoftware.smack.ConnectionListener;
import org.jivesoftware.smack.PacketInterceptor;
import org.jivesoftware.smack.PacketListener;
import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.SmackException.NotConnectedException;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.filter.PacketTypeFilter;
import org.jivesoftware.smack.packet.DefaultPacketExtension;
import org.jivesoftware.smack.packet.Message;
import org.jivesoftware.smack.packet.Packet;
import org.jivesoftware.smack.packet.PacketExtension;
import org.jivesoftware.smack.provider.PacketExtensionProvider;
import org.jivesoftware.smack.provider.ProviderManager;
import org.jivesoftware.smack.tcp.XMPPTCPConnection;
import org.jivesoftware.smack.util.StringUtils;
import org.xmlpull.v1.XmlPullParser;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

/**
 * Sample Smack implementation of a client for GCM Cloud Connection Server. This
 * code can be run as a standalone CCS client.
 *
 * <p>For illustration purposes only.
 */
public class SmackCcsClient {

    private static final Logger logger = Logger.getLogger("SmackCcsClient");

    private static final String GCM_SERVER = "gcm.googleapis.com";
    private static final int GCM_PORT = 5236;

    private static final String GCM_ELEMENT_NAME = "gcm";
    private static final String GCM_NAMESPACE = "google:mobile:data";

    static {

        ProviderManager.addExtensionProvider(GCM_ELEMENT_NAME, GCM_NAMESPACE,
            new PacketExtensionProvider() {
                @Override
                public PacketExtension parseExtension(XmlPullParser parser) throws
                        Exception {
                    String json = parser.nextText();
                    return new GcmPacketExtension(json);
                }
            });
    }

    private XMPPConnection connection;

    /**
     * Indicates whether the connection is in draining state, which means that it
     * will not accept any new downstream messages.
     */
    protected volatile boolean connectionDraining = false;

    /**
     * Sends a downstream message to GCM.
     *
     * @return true if the message has been successfully sent.
     */
    public boolean sendDownstreamMessage(String jsonRequest) throws
            NotConnectedException {
        if (!connectionDraining) {
            send(jsonRequest);
            return true;
        }
        logger.info("Dropping downstream message since the connection is draining");
        return false;
    }

    /**
     * Returns a random message id to uniquely identify a message.
     *
     * <p>Note: This is generated by a pseudo random number generator for
     * illustration purpose, and is not guaranteed to be unique.
     */
    public String nextMessageId() {
        return "m-" + UUID.randomUUID().toString();
    }

    /**
     * Sends a packet with contents provided.
     */
    protected void send(String jsonRequest) throws NotConnectedException {
        Packet request = new GcmPacketExtension(jsonRequest).toPacket();
        connection.sendPacket(request);
    }

    /**
     * Handles an upstream data message from a device application.
     *
     * <p>This sample echo server sends an echo message back to the device.
     * Subclasses should override this method to properly process upstream messages.
     */
    protected void handleUpstreamMessage(Map<String, Object> jsonObject) {
        // PackageName of the application that sent this message.
        String category = (String) jsonObject.get("category");
        String from = (String) jsonObject.get("from");
        @SuppressWarnings("unchecked")
        Map<String, String> payload = (Map<String, String>) jsonObject.get("data");
        payload.put("ECHO", "Application: " + category);

        // Send an ECHO response back
        String echo = createJsonMessage(from, nextMessageId(), payload,
                "echo:CollapseKey", null, false);

        try {
            sendDownstreamMessage(echo);
        } catch (NotConnectedException e) {
            logger.log(Level.WARNING, "Not connected anymore, echo message is not sent", e);
        }
    }

    /**
     * Handles an ACK.
     *
     * <p>Logs a INFO message, but subclasses could override it to
     * properly handle ACKs.
     */
    protected void handleAckReceipt(Map<String, Object> jsonObject) {
        String messageId = (String) jsonObject.get("message_id");
        String from = (String) jsonObject.get("from");
        logger.log(Level.INFO, "handleAckReceipt() from: " + from + ",messageId: " + messageId);
    }

    /**
     * Handles a NACK.
     *
     * <p>Logs a INFO message, but subclasses could override it to
     * properly handle NACKs.
     */
    protected void handleNackReceipt(Map<String, Object> jsonObject) {
        String messageId = (String) jsonObject.get("message_id");
        String from = (String) jsonObject.get("from");
        logger.log(Level.INFO, "handleNackReceipt() from: " + from + ", messageId: " + messageId);
    }

    protected void handleControlMessage(Map<String, Object> jsonObject) {
        logger.log(Level.INFO, "handleControlMessage(): " + jsonObject);
        String controlType = (String) jsonObject.get("control_type");
        if ("CONNECTION_DRAINING".equals(controlType)) {
            connectionDraining = true;
        } else {
            logger.log(Level.INFO, "Unrecognized control type: %s. This could happen if new features are " + "added to the CCS protocol.", controlType);
        }
    }

    /**
     * Creates a JSON encoded GCM message.
     *
     * @param to RegistrationId of the target device (Required).
     * @param messageId Unique messageId for which CCS will send an
     *         "ack/nack" (Required).
     * @param payload Message content intended for the application. (Optional).
     * @param collapseKey GCM collapse_key parameter (Optional).
     * @param timeToLive GCM time_to_live parameter (Optional).
     * @param delayWhileIdle GCM delay_while_idle parameter (Optional).
     * @return JSON encoded GCM message.
     */
    public static String createJsonMessage(String to, String messageId,
            Map<String, String> payload, String collapseKey, Long timeToLive,
            Boolean delayWhileIdle) {
        Map<String, Object> message = new HashMap<String, Object>();
        message.put("to", to);
        if (collapseKey != null) {
            message.put("collapse_key", collapseKey);
        }
        if (timeToLive != null) {
            message.put("time_to_live", timeToLive);
        }
        if (delayWhileIdle != null && delayWhileIdle) {
            message.put("delay_while_idle", true);
        }
      message.put("message_id", messageId);
      message.put("data", payload);

      
      return new Gson().toJson(message);
    }

    /**
     * Creates a JSON encoded ACK message for an upstream message received
     * from an application.
     *
     * @param to RegistrationId of the device who sent the upstream message.
     * @param messageId messageId of the upstream message to be acknowledged to CCS.
     * @return JSON encoded ack.
     */
        protected static String createJsonAck(String to, String messageId) {
        Map<String, Object> message = new HashMap<String, Object>();
        message.put("message_type", "ack");
        message.put("to", to);
        message.put("message_id", messageId);

        return new Gson().toJson(message);
    }

    /**
     * Connects to GCM Cloud Connection Server using the supplied credentials.
     *
     * @param senderId Your GCM project number
     * @param apiKey API Key of your project
     */
    public void connect(long senderId, String apiKey)
            throws XMPPException, IOException, SmackException {
        ConnectionConfiguration config =
                new ConnectionConfiguration(GCM_SERVER, GCM_PORT);
        config.setSecurityMode(SecurityMode.enabled);
        config.setReconnectionAllowed(true);
        config.setRosterLoadedAtLogin(false);
        config.setSendPresence(false);
        config.setSocketFactory(SSLSocketFactory.getDefault());

        connection = new XMPPTCPConnection(config);
        connection.connect();

        connection.addConnectionListener(new LoggingConnectionListener());

        // Handle incoming packets
        connection.addPacketListener(new PacketListener() {

            @Override
            public void processPacket(Packet packet) {
                logger.log(Level.INFO, "Received: " + packet.toXML());
                Message incomingMessage = (Message) packet;
                GcmPacketExtension gcmPacket =
                        (GcmPacketExtension) incomingMessage.
                        getExtension(GCM_NAMESPACE);
                String json = gcmPacket.getJson();
                try {
                	
                	Type collectionType = new TypeToken<Map<String, Object>>(){}.getType();
                	
                    @SuppressWarnings("unchecked")
                    Map<String, Object> jsonObject =
                            (Map<String, Object>) new Gson().fromJson(json, collectionType);   

                    // present for "ack"/"nack", null otherwise
                    Object messageType = jsonObject.get("message_type");

                    if (messageType == null) {
                        // Normal upstream data message
                        handleUpstreamMessage(jsonObject);

                        // Send ACK to CCS
                        String messageId = (String) jsonObject.get("message_id");
                        String from = (String) jsonObject.get("from");
                        String ack = createJsonAck(from, messageId);
                        send(ack);
                    } else if ("ack".equals(messageType.toString())) {
                          // Process Ack
                          handleAckReceipt(jsonObject);
                    } else if ("nack".equals(messageType.toString())) {
                          // Process Nack
                          handleNackReceipt(jsonObject);
                    } else if ("control".equals(messageType.toString())) {
                          // Process control message
                          handleControlMessage(jsonObject);
                    } else {
                          logger.log(Level.WARNING,
                                  "Unrecognized message type (%s)",
                                  messageType.toString());
                    }
                //} catch (ParseException e) {
                //    logger.log(Level.SEVERE, "Error parsing JSON " + json, e);
                } catch (Exception e) {
                    logger.log(Level.SEVERE, "Failed to process packet", e);
                }
            }
        }, new PacketTypeFilter(Message.class));

        // Log all outgoing packets
        connection.addPacketInterceptor(new PacketInterceptor() {
            @Override
                public void interceptPacket(Packet packet) {
                    logger.log(Level.INFO, "Sent: {0}", packet.toXML());
                }
            }, new PacketTypeFilter(Message.class));

        connection.login(senderId + "@gcm.googleapis.com", apiKey);
    }

    public static void main(String[] args) throws Exception {
        final long senderId = 132241975009L; // your GCM sender id
        final String password = "AIzaSyCw_Jggp22ynXhSNaa-19dZYGmsRT8GKzA";

        SmackCcsClient ccsClient = new SmackCcsClient();

        ccsClient.connect(senderId, password);

        // Send a sample hello downstream message to a device.
        String toRegId = "RegistrationIdOfTheTargetDevice";
        String messageId = ccsClient.nextMessageId();
        Map<String, String> payload = new HashMap<String, String>();
        payload.put("Hello", "World");
        payload.put("CCS", "Dummy Message");
        payload.put("EmbeddedMessageId", messageId);
        String collapseKey = "sample";
        Long timeToLive = 10000L;
        String message = createJsonMessage(toRegId, messageId, payload,
                collapseKey, timeToLive, true);

        ccsClient.sendDownstreamMessage(message);
    }

    /**
     * XMPP Packet Extension for GCM Cloud Connection Server.
     */
    private static final class GcmPacketExtension extends DefaultPacketExtension {

        private final String json;

        public GcmPacketExtension(String json) {
            super(GCM_ELEMENT_NAME, GCM_NAMESPACE);
            this.json = json;
        }

        public String getJson() {
            return json;
        }

        @Override
        public String toXML() {
            return String.format("<%s xmlns=\"%s\">%s</%s>",
                    GCM_ELEMENT_NAME, GCM_NAMESPACE,
                    StringUtils.escapeForXML(json), GCM_ELEMENT_NAME);
        }

        public Packet toPacket() {
            Message message = new Message();
            message.addExtension(this);
            return message;
        }
    }

    private static final class LoggingConnectionListener
            implements ConnectionListener {

        @Override
        public void connected(XMPPConnection xmppConnection) {
            logger.info("Connected.");
        }

        @Override
        public void authenticated(XMPPConnection xmppConnection) {
            logger.info("Authenticated.");
        }

        @Override
        public void reconnectionSuccessful() {
            logger.info("Reconnecting..");
        }

        @Override
        public void reconnectionFailed(Exception e) {
            logger.log(Level.INFO, "Reconnection failed.. ", e);
        }

        @Override
        public void reconnectingIn(int seconds) {
            logger.log(Level.INFO, "Reconnecting in %d secs", seconds);
        }

        @Override
        public void connectionClosedOnError(Exception e) {
            logger.info("Connection closed on error.");
        }

        @Override
        public void connectionClosed() {
            logger.info("Connection closed.");
        }
    }
}